Chicago, Rock Island & Pacific (Rock Island) classes R-65 and R-67
United States 1929 85 produced
The first 65 class R-65 Northerns of the Rock Island were delivered by ALCO-Schenectady in 1929 and 1930. They had a driver diameter of 69 inches and were primarily intended for service with freight trains. Some later received 74 inch wheels to be more suitable for passenger trains and were renamed the R-67 class as a result. In the years 1944 and 1946 further R-67b were built, which had larger wheels from the start. Although they had a higher boiler pressure and a larger firebox, they had a smaller tube heating area and a significantly smaller superheater. The 1944 batch were oil fired while the rest were coal fired.
Technical data
General
| Property | R-65 | R-67 |
|---|---|---|
| Built | 1929-1930 | 1944, 1946 |
| Manufacturers | ALCO | |
| Wheel arrangement | 4-8-4 (Northern) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | R-65 | R-67 |
|---|---|---|
| Wheelbase | 13.89 m | 14.35 m |
| Total wheelbase | 26.82 m | 29.24 m |
| Service mass | 196.9 t | 211.8 t |
| Adhesion mass | 120.4 t | 127 t |
| Total mass | 334.9 t | 379.9 t |
| Rigid wheelbase | 5.87 m | 6.02 m |
| Axle load | 30.1 t | 31.8 t |
| Water capacity | 56,781 l | 81,386 l |
| Fuel capacity | 18.1 t (coal) | 20,820 l (oil) |
Boiler
| Property | R-65 | R-67 |
|---|---|---|
| Grate area | 8.203 m² | 8.947 m² |
| Firebox surface | 46.916 m² | 53.698 m² |
| Tube heating surface | 458.756 m² | 371.148 m² |
| Evaporative heating surface | 505.672 m² | 424.846 m² |
| Superheater surface | 208.382 m² | 133.595 m² |
| Total heating surface | 714.1 m² | 558.4 m² |
Power plant
| Property | R-65 | R-67 |
|---|---|---|
| Driver diameter | 1,753 mm | 1,880 mm |
| Boiler pressure | 17.2 bar | 18.6 bar |
| Expansion type | simple expansion | |
| Cylinders | two, 660 x 813 mm | |
Power
| Property | R-65 | R-67 |
|---|---|---|
| Power source | steam | |
| Estimated power | 3,281 kW (4,461 PS) | 3,579 kW (4,866 PS) |
| Starting effort | 296.3 kN | 298.4 kN |
Calculated values
| Property | R-65 | R-67 |
|---|---|---|
| Factor of adhesion | 1 : 3.99 | 1 : 4.18 |
| Optimal speed | 68 km/h | 74 km/h |
| Power-to-weight ratio | 16.7 kW/t | 16.9 kW/t |
| Heating Surface Equivalent | 1,157.0 m² | 960.5 m² |
| Cylinder volume/HSE | 1 : 481.26 | 1 : 579.71 |
| Adhesive weight/Total | 1 : 1.63 | 1 : 1.67 |
| Tractive force/Heating surface | 1 : 8.67 | 1 : 11.16 |
| Grate area/Heating surface | 1 : 87.05 | 1 : 62.42 |
| Firebox/Tube surface | 1 : 9.78 | 1 : 6.91 |
| Total/Superheater | 1 : 2.43 | 1 : 3.18 |
